Similar presentations

2Anatomy of the Liver1 Most metabolically complex organ2 main, 2 smaller lobeEight segmentsLobulesDual blood supplyPortal vein (75%)Hepatic artery (25%)Sinusoidal hepatocyte platesEndothelial, Kupffer’s, Fat-storing, PitThe liver is the most metabolically complex organ. It is made up of two main lobes, the right and the left, and two smaller lobes, the posterior and inferior. The lobes are divided into eight segments by the distribution of the circulatory system. The smallest functional unit of the liver is the lobule, which is bound by four to five portal triads, and contains a central hepatic venule. The liver is serviced by a dual blood supply, with 75% of the blood coming from the portal vein and 25% from the hepatic artery. The lobules are made up of hepatocyte plates arranged into a sinusoid. The lining of the sinusoids is made up of 4 types of cells – endothelial cells, which help in endocytosis, Kupffer’s cells, which are involved in the removal of noxious substances, fat-storing cells, which store vitamin A, and pit cells, which act as natural killer cells.

3Functions of the Liver1 Metabolism Bile synthesis Glucose regulationAmino acid catabolismDrug neutralizationBile synthesisDigestion of fatCholesterol catabolismStored in gallbladderReleased by CCK from SIThe main function of the liver is metabolism of carbohydrates, proteins and fats. It also functions in glucose level stabilization. When the blood concentration of glucose is too high, the liver uptakes and stores glucose as glycogen, through the process of glycogenesis. When the blood concentration of glucose is too low, the liver breaks down the stored glycogen back into glucose via glycogenolysis. Other metabolic functions of the liver include animo acid catabolism and drug detoxification. Bile synthesis is another main function of the liver. Bile is needed by the body for the digestion and absorption of fats. Bile is made in the liver by cholesterol catabolism, and stored in the gallbladder for future use. Bile release is signaled by the secretion of cholecystokinin by the small intestine.

4Current State of Liver TE2Regeneration- One of few organs able to regenerate- Full functional recovery after 80% hepatectomyIn Situ Regeneration-Vascularization for increasing hepatocyte trasplants in vivo-Ohashi et al. have developed a method to form stabletransplants of liver cells under the kidney capsule in the miceYokoyama, T., Ohashi, K., Kuge, H., Kanehiro, H., Iwata, H., Yamato, M. and Nakajima,Y. (2006) In vivo engineering of metabolically active hepatic tissues in aneovascularized subcutaneous cavity. American Journal of Transplantation, 6, 50±59.